There’s a lot of exciting stuff you’ll see in “Harry Potter and the Chamber of Secrets” – and then there’s the stuff you won’t see.

Like Harry dancing the macarena. On a table. In the Great Hall.

Just ask Emma Watson, who plays Hermione to Daniel Radcliffe’s Harry.

“As you can imagine, after working in the Great Hall for a week, with 300 children and the fires going, it was absolutely boiling,” she tells The Post.

“The food was bad and it was so boring. Finally, Dan got up and danced on the table. He did the cancan, the macarena – he got everybody to laugh!”

Then, she added, with a touch of Hermione’s primness:

“I still don’t think he’s ready to give up his day job, though.”

Ready or not, Harry Potter and friends are back – this time in “Harry Potter and the Chamber of Secrets,” which opens Friday.

This time, Harry, Hermione and Ron (Rupert Grint) find themselves up against a fearsome beast hidden away in the bowels of the school, where it surfaces periodically to petrify students and the occasional cat.

And then there’s the new Defense Against the Dark Arts teacher, the golden-haired Gilderoy Lockhart, played by Kenneth Branagh.

“Probably my favorite scene was the Lockhart scene, because there’s lots of crawling around and getting all dreamy, because I love Lockhart, apparently,” she says.

But as Branagh told The Post, there was a lot of unscripted flirting going on, too – especially in the classroom scenes. Emma agrees.

“We had enough romance on the set to make a soap – not with me,” the 13-year-old adds, quickly.

“Me and Dan and Rupert are really good friends.”

The biggest challenge, Emma says – besides sitting still all those days in the Great Hall and, in another scene, making herself cry – was learning the lines she speaks as Hermione.

“To be honest with you, she speaks like a dictionary,” Emma sighs. “She uses three-syllable words in every sentence. I can’t even understand what she says sometimes.”

Does that mean Emma isn’t an A student?

“No way,” she enunciates. “Definitely not! I’m not obsessed with books and exams. I much prefer sports and being with my friends.”

That said, she’s already gearing up for the third film, “Harry Potter and the Prisoner of Azkaban,” which starts shooting in January.

Reports say it may well be the last Potter film she and Daniel and Rupert do together – they seem to be growing faster than J.K. Rowling’s characters – but Emma is non-commital.

“I’m just going to go with the flow,” she says. “It’s been really good fun.”